Skill cranes have been in use for many years wherein a plurality of various prizes are contained within a cabinet having a claw mechanism contained therein, and actuated by a person outside of the cabinet, whereby an attempt is made to grasp and retrieve one of the prizes from the cabinet within a predetermined period of time.
A claw crane (also called a variety of other names, such as claw machine) is a type of arcade game known as a merchandiser, commonly found in video arcades, supermarkets, restaurants, movie theaters, shopping malls, and bowling alleys.
A claw crane consists of many parts, but the basic components are a printed circuit board (PCB), power supply, currency detector, credit/timer display, joystick, wiring harness, bridge assembly, and claw. The claw has two or more fingers, although most claws have three.
The cabinet is usually constructed of medium-density fiberboard (MDF). Some cabinets are made of aluminum alloy, which makes it easier to relocate as well as cheaper to produce. The window at the front of the machine is normally made of glass or a cheaper-to-manufacture substitute, such as acrylic. The marquee is a branded graphic (sometimes created specifically for restaurants or an operator's business name) behind a PLEXIGLASS front.
A claw vending machine consists of prizes, usually plush toys or alternatives such as jewelry, capsuled toys, hats, balls, dolls, shirts, candy and electronics. More expensive prizes are sometimes placed in a plastic bag so the toy is harder to pick up. The player inserts money or tokens into the machine, which then allows the player to manipulate a joystick that controls the claw for a variable amount of time, (controlled by the operator) usually 30 seconds, and rarely even a minute. The player is able to move the claw back, forth, and sideways. Some machines allow the user to move the claw after it has partially descended.
At the end of the play time (or earlier if the player presses a trigger button on the joystick), the claw descends and makes an attempt to grip. After making the gripping attempt, the claw then moves over an opening in the corner of the case and releases its contents. If the player is successful, then the prize the claw is holding is dropped into the opening and dispensed through a chute into a hatch for collection.
An alternative version of the machine, popular in arcades, is the two button version: one marked with a forward arrow, one with a right arrow. The crane starts near the front, left side of the machine and the user presses first the forward button to move the crane towards the back of the cabinet. Once the button is released the crane stops moving and the button cannot be used again, thus requiring the user to judge depth accurately in one attempt. After this, the right button becomes active in a similar way and as soon as it is released, the crane drops to a certain depth and then raises, closing its claw on the way and returning to the drop hatch in the front left corner. These versions are generally considered to be more difficult. The button type machines typically do not feature the timers which are commonly found on joystick type machines.
The success rate of winning a prize is dependent on several factors including operator settings, player skill, type of machine, and the prizes available (size, density, and distribution). A prize may be lost due to player inexperience, player error in manipulating the claw, the weakness of the claw, or the specific crane configuration. Many modern cranes use a computer to determine an expected payout percentage based on the operator's settings. All modern claw machines incorporate some means for the owner to adjust at least the strength of the claw's grip and how closely the claw's fingers pull together, usually with screws on the mechanism or potentiometers on the PCB.
Even on older machines, the grip strength can be adjusted by adding circuit components or additional hardware. Some machines incorporate a feature called two-level claw power, which, when enabled, causes the claw to at first grip at full strength, but then gradually weaken its grip to the normal level after a brief delay. This can cause the crane to initially pick up the prize, but then drop it.
Modern claw machines are fully computerized and are remotely programmable by the owner (via a hand-held device). Settings and features commonly available include: Claw strength and aperture; Motion speed, in any direction (that is, the claw can be made to drop slowly but come up quickly, or move right faster than it moves forward); Pick-up strength and retain strength can be specified separately, as well as the delay between pick-up and return.
Currently there is no claw or crane machine known that uses an adjustable prize chute as one of the factors in controlling payout and the amount of skill required to win a prize.